Crunching The Numbers
How we arrived at our rankings.
THE CURRENT TEXAS SCHOOL RATING SYSTEM—THE ONE THAT EVERYONE KNOWS—is based on the percentage of students in a school who pass the Texas Assessment of Academic Skills tests (commonly known as TAAS) with a grade of 70. Schools with the highest percentage of passing students are designated "exemplary;" schools with the lowest percentage are said to be "low-performing."
The ratings listed here go well beyond that simple standard in two important ways. First, they judge students based on the more rigorous measure of TAAS proficiency, which is roughly equivalent to a grade of 85. The idea is that passing—once considered a near miracle in many districts—is no longer good enough. Students who achieve proficiency are really learning as opposed to just scraping by. Second, schools are compared not with every other school in the state but only with those whose student bodies are similar to or worse off than theirs, socioeconomically speaking. The current TAAS ratings put high schools in, say, Plano and Brownsville side by side for purposes of measurement, even though they differ greatly in the number of students who speak English as a second language or are economically disadvantaged (meaning they receive federally subsidized lunches). Our ratings take those differences firmly into account.
With these ideas in mind, our rating system (which was developed by the nonprofit education foundation Just for the Kids) determines your school's "opportunity gap"—the difference between its TAAS proficiency and the average TAAS proficiency of the top schools (ten for elementary, five for middle and high school) that have similar or more disadvantaged students. A positive opportunity gap means your school is among the best of its kind. A gap of between 0 and 5 is extremely good. For elementary schools, a gap of 25 or worse is considered poor. For middle and high schools, a gap of 15 or worse is poor.
The opportunity gap is the basis for our star system. We've divided the roughly 5,400 schools on our list into four socioeconomic groups, from richest to poorest, and ranked them according to their gaps. A five-star school is in the top 20 percent of schools in its socioeconomic group. A four-star school is in the next 20 percent, and so on down to one-star schools, which are in the bottom 20 percent.
When you enter the school's name in search field the results will look like this:
Crockett Elementary School, Abilene School District
| Stars | RM | EcD | Gap |
 |
71/71 | 66 | -22 |
Here is how to interpret these numbers. Crockett Elementary, in the Abilene Independent School District, is a three-star school. This means it ranks somewhere in the fortieth to sixtieth percentile of schools in its socioeconomic group. The numbers in the second column tell you the school's proficiency in reading (R) and math (M): 71 percent of its students are proficient in both subjects. The third column tells you the percentage of economically disadvantaged students at the school, which determines its socioeconomic grouping. The fourth column is the school's opportunity gap—in Crockett's case, 22, which puts it a good distance below the best schools in its group.
While we've given you quite a bit to chew on, space considerations prevented us from publishing every last piece of data germane to the ratings. For instance, you won't find the percentage of students proficient in the TAAS writing test, which is administered in elementary and middle schools and figures in the opportunity-gap calculation. (If two schools with similar student bodies and similar reading and math scores received a different ranking in our pages, it's possible that students at the school with more stars did better on the writing test.) Nor will you find a host of lesser factors that contribute to the ranking of high schools, including the TAAS exit-level test in writing, the end-of-course algebra exam, and the percentage of ninth graders promoted to the tenth grade. If you really, really want to see everything used to calculate the ratings, log on to the Just for the Kids Web site, just4kids.org.
One last cautionary note: Not every single public school in Texas is represented here. For reasons that have to do with the reliability and the availability of data, we've left out, for instance, extremely small schools with fewer than five continuously enrolled students in a grade, schools that have opened since 1997, and high schools that do not have both grades nine and ten. If your school is missing from our list and you're not sure why, check out the Just for Kids' Web site for a more thorough explanation.
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